Wrecks of Aiyo, Kenbu, Shin-ai and Taimei Maru's

 Second World War 1939-1945, military, navy, ship, shipwreck

On the 2nd of March 1943, the Imperial Japanese Army Troopships Aiyo Maru, Kembu Maru, Shin-ai Maru and Taimei Maru were all sunk in this general area by combined air forces of the United States Army Air Corps and Royal Australian Air Force in what is now known as the Battle of the Bismarck Sea.

Operating as part of a massive reinforcement convoy codenamed "Operation 81", the ships were under a heavy escort of six battle-experienced Destroyers and were enroute from Rabaul to Lae with 5,954 troops of the 51st Division, IJA 8th Army, munitions, supplies and vehicles crammed into their hulls. Departing Rabaul at 2330hrs on February 28th, the convoy steamed under strict radio silence to preserve the secrecy of their movements, however Allied codebreakers were already well aware of the convoy and its intended destination. Shielded by low clouds and thus able to elude the numerous Allied recon aircraft scouting for it, the convoy managed to get to waters off Cape Gloucester before the weather broke.

Coming under attack by B-17's throughout the daylight hours of March 2nd, the convoy lost one troopship and suffered damage to several others but was otherwise able to continue through the Dampier Strait and into the Huon Gulf during the night and into the early morning without further incident. Dawn on March 3rd found the ships of Operation 81 only 80 miles from their destination, and with it brought the arrival of some thirty "Zero" fighters to provide air cover as the ships made their best speed towards Lae. Though the convoy was now under the air cover umbrella provided by Lae and its satellite airfields, it was now also within reach of the Allied air base at Milne Bay and its airwing of RAAF medium bombers, and after the first enemy recon aircraft were reported closing in at 0755hrs, the entire convoy began defensive maneuvers and prepared to fight.

Soon set upon by over 100 Allied aircraft ranging from fighters to heavy bombers throughout the day, the convoy's escort and air cover where overwhelmed by the sheer number of attackers coming from multiple directions and altitudes. In short order the majority of the convoy's escorts were hit and in distress, including the Destroyer Squadron Flagship which had lost its Stern and suffered numerous casualties which included the Convoy Commander, sending the formation into disorder. Allied medium bombers were soon slicing through the convoy at mast height, Bristol Beauforts joining B-25's in the first Pacific-theatre use of skip-bombing while A-20 Havocs & Bostons, Bristol Beaufighters and B-25H gunships soon followed, pouring withering machine gun and cannon fire onto the now-vulnerable transports.

By the time the first wave of attacking aircraft withdrew, most if not all of the convoy's transports were on fire, disabled or sinking. With their escort ships in similar straits, the convoy had little chance of defending itself when enemy aircraft returned in the early afternoon in greater numbers, and by nightfall on March 3rd the Aiyo, Kenbu, Shin-ai and Taimei Maru's had all gone down, taking the majority of their crews, passengers and their cargo with them. Losses in soldiers and crew among the four ships are listed as follows:
Aiyo Maru: 45 crewmen and 278 soldiers
Kenbu Maru: 20 Crewmen (Approximate)
Shin-Ai Maru: 18 crew, 45 members of her anti-aircraft gunners, and an unknown number of troops
Taimei Maru: 44 crew and 35 soldiers

Further info on the ships:
en.wikipedia.org/wiki/Japanese_transport_Aiyo_Maru
en.wikipedia.org/wiki/Japanese_transport_Kembu_Maru
en.wikipedia.org/wiki/SS_Sin-ai_Maru_(1921)
en.wikipedia.org/wiki/SS_Taimei_Maru_(1936)

Further Info:
www.combinedfleet.com/bismksea.htm

Australian Newsreel Footage of the Battle:

www.youtube.com/watch?v=azanISsx19c